The romance of living with shadow

A lovely little passage from a book I am reading at the moment, that describes the allure of living with shadow.  We are captivated by fog.

I fell to dwelling upon the romance of the fog. And romantic it certainly was–the fog, like the grey shadow of infinite mystery, brooding over the whirling speck of earth; and men, mere motes of light and sparkle, cursed with an insane relish for work, riding their steeds of wood and steel through the heart of the mystery, groping their way blindly through the Unseen, and clamouring and clanging in confident speech the while their hearts are heavy with incertitude and fear.

— Jack London, The Sea-Wolf